Yes, just like a sandwich can be made up of many delicious meats, cheeses, vegetables and condiments to suit your taste, assessments are often customized using different item scales that work together to measure job relevant competencies in the best way possible. Generally you will start with at least the basic ingredients when making a sandwich (e.g. ham, pickles, mustard), rather than creating each ingredient from scratch. You’ve had the ham before; it’s quality ham, no need to start raising heritage pigs in your back yard. Much the same way, we often use a variety of item scales (test questions that are grouped together based on a number of characteristics) that have proven to work in the past. So instead of creating a whole new set of questions each time a test is needed, we often use these gold standard item scales to create an assessment that is reliable, predictive, job relevant and suitable for the level of testing needed.
It is possible to create new item scales, and entirely new assessments, but there is a lot of leg work that goes into making sure the assessment is functioning the way that it should. Work must be done to make sure the overall assessment results are predictive of performance, that the test items are not too easy or difficult, that the pass rates are acceptable and that the assessment is measuring what it intends to measure and not something else (imagine biting into your Reuben and finding only bologna!). This is most commonly accomplished through an investigation of how the assessment relates to actual job performance, otherwise known as a criterion related validation study.